How do you think Shikamaru's technique would improve if he had Sharingan to help with his strategy making?
I think what Shikamaru's greatest weapon is his brain. Having an eye technique would hinder his thinking process, I wouldn't think it'll help rather...it'll probably hinder him.
I think ineffective; the main positives of sharingan is to read taijutsu and counter it or copy ninjutsu, neither of which shikamaru is strong at due to his lack of chakra and knowledge of.
As mentioned, the edge he has over other ninja is his brain, although if this sharingan somehow meant he also had a lot more chakra (say he was an uchiha, they naturally have more chakra than others) then it would be a plus. It's really annoying, how many times have we seen shikamaru running out of chakra? You think if only he had more chakra, he could be phenomenal.
its irrelevant, as Shika's powerful enough with his analytical abillity to pwn his enemies without needing any fancy Kekkei Genkai. (not dissing le Sharingan, it's awesome...it's just not neccessary for Shikamaru )
I think of this situation as what happened to Kakashi, because kakashi was smart before he got his sharingan. But, after he got the eye it took him to another level. Well with shikamura brain and the ability to predict someone's moves would make him a force to be reckoned with.